Valve-gear for explosive-engines



PATENTED EEB. 2, 1904.

J. M. JOHANSON. VALVE GEAR EOE EXPLOSIVE ENGINES.

APPLICATION FILED MAY` 8, 1903.

N0 MODEL.

Illll III W/TNESSES:

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UNITED STAT-Es l.Ionen M. JoHANSoN, oEI CAMBRIDGE, MASSACHUSETTS.I

Patented February 2,1904.

lPATENT OFFICE.

VALVE-GEAR FOR EXPLOSlVE- ENGINES- SPECIFICATION forming part of Lettere ratentNe. 751,293, dated February 2, 1904.

i Application filed May 8, 1903. Serial No. 156,176. (No model.)

lTo all whom t may concern:

Be it known that I, JOHAN M. J CHANSON, a subject of the King of Sweden and Norway; and a resident of Cambridge, in the county of Suffolk and State of Massachusetts, have invented a new and 'Improved Valve-Gear for Explosive-Engines, of which the'following is afull, clear, and exact description.

This invention relates to a gear intended especially for operating the exhaust-valves of internal-combustionengines.

The principal object ofthe invention is to provide means by which the valve may be allowed to open outward as contradistinguished from inward against the cylinder-pressure and which means, while permitting this outward opening movement, will nevertheless hold the valve seated with absolute rmness during the expansive period of the cycle.

A .further object of the invention is to avoid backlash on the gearing of the cam-shaft and to prevent the operation of the valve from materially loading said shaft and the connected parts. i

These ends I attain, briefly stated, by providing a slide between which' and the valvestem bears a link having rolling connection with the slide and valve-stem, said slide moving across the longitudinal axis of the valvestem, so that the latter will be operated to-seat the valve, the extent of the valve movement depending upon the degree of movement of the .link from alinement with the valve-stem to an inclination to the stem. Said slide is operated by a rocker arm or lever from a cam driven from the engine-shaft, this cam acting to hold the slide immovable during all periods of the cycle excepting the exhaust period, whereupon the valve is allowed to open by reasonof the cylinder-pressure, assisted, if necessary, bya spring applied to start the opening tion, and Fig. 2 is an enlarged sectionl on the valve, this valve seating in the port andopening outwardas shown. The stem` 14e of the valve is fitted in a bushing `or cap 15, which is fastened in the exhaust-chamber and provided with an inward extension 15, serving to limit the opening movement of the valve 12.-

Formed, preferably, integral with the engine-frame is a shelf 16,Y which projects out horizontally and is formed, as 'best shown in Fig. 1, with an inclined upper face. Above this shelf 16 is formed a Shoulder 17, and to the parts 16 and 17 a face-plate 18 is fastened by means of bolts 19 or the like, these bolts permitting a slight vertical adjustment of the plate 18 and said parts 16, 17, and 18 forming a case or inclosure for the principal parts of the Valve-operating gear. The face-plate 18 is provided with inward extensions 18, and between said extensions and kthe sloping upper face of the shelf 16 is arranged a bedplate 20, said plate having an inclined bottom face corresponding to the upper face ofthe shelf 16. The upper face of the;bedplate 20 is horizontal. Screwing in the lend wal-l of theface-plate 18 is an adjusting-screw 21, by which the lbed 20 may be moved on the shelf 16, and by this means the elevation of the bedplate may be regulated yat will. To effect this regulation, it is necessary to loosen the fastenings 19, so as to permit the face-plate to risecorrespondingly. ,v

-Mounted on the bed-plate 20 between the extensions '18 of the face-plate 18 are a series of rollers or other antifriction devices 22, Such rollers carrying a slide 23. This slide is located in the before-mentioned case formed by' IOO.

lever 28. Between said lever and the slide a spring 29 bears, this spring being tightly coiled and encircling the stem 27. The lever 28 extends downward and is actuated by the cam 30 on the cam-shaft 31, suitably geared with the engine-shaft 32.

The lower end of the valve-stem is fastened to a block 33, which slides in a vertically-extending guidcway 18b in the case 18, and between this block 33 and the slide 23 is located the before-mentioned link. This link comprises a web or body portion 34:, having transversely-extended concave ends 34a. In said concave ends are arranged the roller-like bearings 35 and 36, said bearings being connected by straps 37, so as to hold them firmly engaged with the link. The rollers 35 and 36 are held engaged with the slide 23 and block 33 by means of straps 38 and 39, formed on or fastened to the respective elements 23 and 33. By this means the elements 23 and 33 are connected by the link in such a manner as to insure the operation of the three parts with the least possible friction, but at the same time providing' for entire strength and certainty of'action.

18c indicates a socket for an oil-cup or other lubricant, and this socket communicates with a passage 33c in the block 33, this communication being periodical upon the reciprocation of said block. The roller-bearing 36 has passages 36L formed therein, as shown, these passages communicating with the passage 33C and with a passage 34 in the web 34, said passage leading downward to the bearing 35. This provides for the thorough lubrication of the parts 33, 36, and 35, the roller 35 being seated in a cavity in the top of the slide 23, as best shown in Fig. 1. To enable the surplus oil to escape from the locality of the rollers 22, I provide an orifice 16a in the bot- 'tom of the shelf 16, by which the surplus oil may be drained off.

In the operation of the invention as the circular part of the cam 30 engages the lever 28 the force of the said lever is first communicated to the spring 29 and the slide 23 is moved inward until arrested by the parts 25 and 26, this spring' 29 being of greater strength than the spring 24. The parts 25 and 26 should beso adjusted as to allow the slide to move sufH- ciently to bring the link into near proximity to alinement with the valve-stem; but actual alinement should not be permitted. The movement of the slide 23 having been arrested and the movement of the lever 28 continuing, said lever will close up the spring 29 and exert a positive pressure on the slide. The valve 12 will have been seated at the end of the movement of the slide, and then when the spring 29 is closed and the positive pressure of the lever is applied to the slide the valve is held seated by a pressure which is unyielding. At the same time there is no perceptible load on the cam-shaft, since the circular part of the cam will bc turning against the lever. As the rotation of the cam continues and the exhaust period is reached the cam-pressure on the lever 28 will cease and the cylinder-pressure, acting on the valve 12 and assisted by the spring 29, will throw downward the sliding block 33. Owing to the inclined position of the link and the antifriction-mountings of the slide, the latter will be moved outward, and the inclination of the link to the valve-stem will be gradually increased until the valve movement is arrested by the extension 15 of the cap or bushing 15. Upon the continued rotation of the cam 3() the closing movement will begin and the above-described operations will be repeated. Owing to the fact that the link is always at an inclination to the valve-stem and the slide is mounted to move with the least possible friction, the instant the pressure of the lever 28 is relaxed the slide will move outward under the action of the cylinder-pressure- Consequently the spring 26 is not strictly necessary. I prefer, however, to provide it as a precaution. The adjustable bed 20 enables me to take up all wear on the parts, so as to insure their effective operation. This wear may also be partly accounted for by adjusting the stop 24. By means of this construction it will be seen that the objects of my invention are fully attained. The valve is not opened against the cylinder-pressure, as is usually the case in prior structures, and the opening movement of the valve exerts on the lever 28 and then on the cam 30 a pressure which is in the direction of the cam-shaft, and consequently rather than retarding the camshaft in its operation my improved gear tends to assist the movements thereof. When the valve is closed and the link is nearly in alinement with the valve-stem, the greater part of the pressure on the valve is borne by the slide 23, but a decidedly minor portion being communicated to the lever 28. Consequently, owing to this fact and to the fact that when the valve is closed the circular part of the cam' 30 is running on the lever 28, the work of holding the exhaust-valve closed involves no perceptible load on the engine.

Various changes in the form, proportions, and minor details of my invention may be resorted to at will without departing from the spirit and scope thereof. Hence I consider myself entitled to all such variations as may lie within the intent of my claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patentn 1. In a valvegear, the combination with the valve, of a slide movable across the line of movement of the valve, a connection between the valve and slide, said connection including a link pivoted at its ends, and means for actuating the slide. 1

2. In a valvegear, the combination with the valve, of a slide movable across the line of movement of the valve, a valve-stem,` a link IOO IIO

pivotally connected tothe slide and valve-stem,

and means for operating the slide.

3. In a valve-gear, the combination with the valve, of a slide movable across the line of movement of the valve, a connection between sive spring bearing between the slide and the operating member.

5. In a valvegear, the combination with the valve, of a slide movable across the line of movement of the valve, a connection between the valve and slide, said connection including a pivoted link, means for mounting the slide, such means including rollingantifriction bearing members, and means for operating the slide.

6. In a valve gear, the combination with the valve, of a slide movable across the line of ,movement of the valve, a connection between the valve and slide, said connection including a pivoted link, means for mounting the slide, such means including rolling antifriction bearing members, and means for operating. the. slide, said means including an expansive springu acting between the slide and operating member. 7 In a valve-gear, thev combination with the valve, of' a slide movable across the line of movement ofthe valve, a connection between the slide and valve, said connection including a pivoted link, a spring pressing the slide in one direction, and means for operating the slide in the other direction. y 8. In a valve-gear, the combination with the valve, of a slide movable across the line of movement of the valve, a connection between the slide and valve, said connection including a pivoted link, a spring pressingthe Vslide in one direction, and means for operating the slide in the other direction, the means for operating the slide including an expansive spring actuated between the slide and the operating member. e

9. In a valvegear, the combination with the valve, lof a slide movable across the line of movement of the valve, a connection between the valve and slide, such connection including a pivoted member, means for mounting the slide, such means including antifriction roller bearing devices, and meansfor operating the Slide.

10. In a valve-gear, the combination with the valve, of a support, a bed adjustable theref on for the purpose'specifed, a slide mounted on the bed, a connection between the slide and valve, such connection including a pivoted member, and means for operating the slide.

11. In a valve-gear for internal-combustion engines the combination with the outwardlyopening exhaust-valve, of a pivoted link having connection with the valve, and means for varying the inclination ofthe link with respect to the line of movement of the valve,

Whereby'to operate the valve.

12. In a valve-gear for internal-combustion engines, the combination with the outwardlyopening exhaust-valve, vof a pivoted link connected therewith, a slide also having connection with the link and movable across the line of movement ofthe valve, and-means for operating the slide.

13. In a valve-gear, the combination with the valve, of a pivoted link having connection therewith, and means for varying the incliengaged with the slide andthe otherrollerv with the valve connection.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' JOHAN M. JOHANSON. i

CHARLES E. ANDERSON, OLAF MYHRER.

IOO 

